Naslov
Micrometer-Sized Thin Films of the Nb0.7Ge0.3 Weak-Pinning Superconductor

Autori
Babić, Dinko ; Nussbaumer, Thomas ; Strunk, Christoph ; Schoeneneberger, Christian ; Suergers, Christoph

Izvornik
Physical review. B. (2469-9950) 66 (2002);

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
mixed state; noise; vortex motion

Sažetak
We report high-resolution measurements of voltage (V) noise in the mixed state of micrometre-sized thin films of amorphous Nb//0.7//Ge//0.3//, which is a good representative of weak-pinning superconductors. There is a remarkable difference between the noise below and above the irreversibility field B//irr. Below B//irr, in the presence of measurable pinning, the noise at small applied currents resembles shot noise, and in the regime of flux flow at larger currents decreases with increasing voltage due to a progressive ordering of the vortex motion. At magnetic fields B between B//irr and the upper critical field B//c2 flux flow is present already at vanishingly small currents. In this regime the noise scales with (1-B/B//c2)^2 V^2 and has a frequency (f) spectrum of 1/f type. We interpret this noise in terms of the properties of strongly driven depinned vortex systems at high vortex density.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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